The present invention is directed to a joint temporal and spatial antenna processing scheme useful in wireless communication applications, such as short-range wireless applications.
Antenna diversity schemes are well known techniques to improve the performance of radio frequency (RF) communication between two RF devices. Types of antenna diversity schemes include antenna selection diversity and maximal ratio combining. In an antenna selection diversity scheme, a radio communication device selects one of N (e.g., two) antennas for transmission to a particular communication device based on which of its N antennas best received a signal from that radio communication device. On the other hand, maximal ratio combining schemes involve scaling the signal to be transmitted with a complex antenna weight associated with a corresponding one of a plurality of antennas. A signal received by a plurality of antennas can also be weighted by a plurality of complex receive antenna weights. Selection of the antenna weights to optimize communication between two communication devices determines the performance of maximal ratio combining schemes.
A joint maximal ratio combining antenna processing technique is one in which a first communication device, having a plurality of antennas, weights a signal to be transmitted by its antennas to a second communication device also having a plurality of antennas. The second communication device weights and combines the received signals received by its antennas. The transmit weights and receive weights are determined to optimize the link margin, e.g., optimize the signal-to-noise ratio of signals received by one device from the other. Techniques related to joint maximal ratio combining, also called composite beamforming (CBF), are the subject matter of above-identified commonly assigned co-pending application. These techniques significantly extend the range of communication between the two communication devices.
An approach is desired for a joint maximal ratio combining technique that requires relatively low complexity computations be performed in a communication device.